Rod Bearing Failure Analysis
- Thread starter Taylor
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Originally Posted By: punisher
Is the tab/key just wiped out on the shell on that cylinder and not the others? Just curious how that bearing spun and didn't inflict anymore damage to the big end or the shell itself. Google the numbers from the bearing shells and see what it is. Does it match the other shells? I can't get over the lack of damage. Maybe it spun before and someone cleaned it up and threw in another bearing. Maybe the grooves on the back of the shell are just imprints from the rod/cap. Just throwing it out there. Any signs of discoloration/blueing on the rod/cap?
The tabs not wiped, it's just the pic. I googled the numbers to no avail. They are all the same though
Is the tab/key just wiped out on the shell on that cylinder and not the others? Just curious how that bearing spun and didn't inflict anymore damage to the big end or the shell itself. Google the numbers from the bearing shells and see what it is. Does it match the other shells? I can't get over the lack of damage. Maybe it spun before and someone cleaned it up and threw in another bearing. Maybe the grooves on the back of the shell are just imprints from the rod/cap. Just throwing it out there. Any signs of discoloration/blueing on the rod/cap?
The tabs not wiped, it's just the pic. I googled the numbers to no avail. They are all the same though
It may just be the picture (I'm viewing it on a small screen) but I don't see any threads in one bolt hole and the cap looks like it's been peened a bit....like it was a little loose. Can you mic the crank journal/
Originally Posted By: Taylor
Rod side journal bore;
Hard to tell in the pic, but is that a crack where the left side bolt goes?
Rod side journal bore;
Hard to tell in the pic, but is that a crack where the left side bolt goes?
Spun bearing. The lining on the ID looks good, but the bearing has been spinning in the rod big end bore. Probably insufficient crush on the bearing. Even if the rod bolts were torqued correctly, if there is not enough bearing crush, the bearings will spin. Since the big end of the rod is now grooved, it probably can't be reconditioned to be good. And the picture of the rod looks like it is a fracture-split type, which probably can't be reconditioned.
How much do you want to dig into this thing? Maybe you could just go buy a remanufactured engine with a warranty and swap it in. I have a feeling the more you dig into this one, the more you'll find is wrong with it.
How much do you want to dig into this thing? Maybe you could just go buy a remanufactured engine with a warranty and swap it in. I have a feeling the more you dig into this one, the more you'll find is wrong with it.
The rod face looks peened like it was loose? Maybe it's just the picture. What do the mains look like....have you pulled one? It still bothers me that the rods appear "wet" (with oil) which is inconsistent with spun bearings (usually they're dry and burnt looking due to extreme heat) and it's pretty odd that all bearings would spin.
I wish I had a better view of the bearings. I would suggest pulling a main if you haven't yet. If you can't pull one, maybe you could mic a crank journal and check against spec? Does the rod cap/bearing smell burnt?
I wish I had a better view of the bearings. I would suggest pulling a main if you haven't yet. If you can't pull one, maybe you could mic a crank journal and check against spec? Does the rod cap/bearing smell burnt?
Is it possible this was a Cash for Clunkers car? That could explain the unusual bearing wear.
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The very first photo shows very tiny small dots or pockets, which indicate fatigue. This thing probably had the living daylights beat out of it.
Originally Posted By: Silverado12
Is it possible this was a Cash for Clunkers car? That could explain the unusual bearing wear.
that would show up on the title. He said that it looked like it has changed hands quite a bit recently, that same check would have shown cash for clunkers (assuming it wasn't an error or fraud). still, some evidence would probably be found.
Is it possible this was a Cash for Clunkers car? That could explain the unusual bearing wear.
that would show up on the title. He said that it looked like it has changed hands quite a bit recently, that same check would have shown cash for clunkers (assuming it wasn't an error or fraud). still, some evidence would probably be found.
I suspect you'll end up pulling it anyway to make repairs. Might make more sense to locate a pre-used engine. It's hard to say what you've got going on there and it might be risky to throw dollars at it. Good luck!
The con rod and cap mating faces sure look weird but it may just be the picture....the faces look like they were working on each other, aka loose.
The con rod and cap mating faces sure look weird but it may just be the picture....the faces look like they were working on each other, aka loose.
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